• Users Online: 12
  • Print this page
  • Email this page

Table of Contents
Year : 2019  |  Volume : 6  |  Issue : 3  |  Page : 151-154

Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma

1 Department of Internal Medicine, Division of Hematology/Oncology, Sijhih Cathay General Hospital; Department of Medicine, School of Medicine, Fu Jen Catholic University, New Taipei, Taiwan
2 Division of Pathology, Sijhih Cathay General Hospital, New Taipei, Taiwan
3 Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, New Taipei, Taiwan

Date of Submission03-Jan-2019
Date of Decision03-May-2019
Date of Acceptance12-May-2019
Date of Web Publication20-Aug-2019

Correspondence Address:
Dr. Hui-Wen Liu
Department of Internal Medicine, Division of Hematology/Oncology, Sijhih Cathay General Hospital, No.2, Ln.59, Jiancheng Rd., New Taipei 221
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JCRP.JCRP_13_19

Rights and Permissions

Primary thymic mucinous adenocarcinoma is an extremely rare type of thymic carcinoma that is resistant to radiation and chemotherapy. We present a case of primary thymic mucinous adenocarcinoma with disseminated metastases and rapid progression, after concurrent chemoradiation and platinum-based doublet chemotherapy. Case and literature review also revealed poor outcomes for primary thymic mucinous adenocarcinoma patients receiving surgery and adjuvant therapy. We concluded the poor response of either resectable or unresectable primary thymic mucinous adenocarcinoma.

Keywords: Mucinous, primary adenocarcinoma, thymic carcinoma, thymic epithelial tumors

How to cite this article:
Liu HW, Liu CY, Yeh YC. Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma. J Cancer Res Pract 2019;6:151-4

How to cite this URL:
Liu HW, Liu CY, Yeh YC. Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma. J Cancer Res Pract [serial online] 2019 [cited 2020 Dec 3];6:151-4. Available from: https://www.ejcrp.org/text.asp?2019/6/3/151/264839

  Introduction Top

Primary thymic mucinous adenocarcinomas are extremely rare type of thymic epithelial tumors (TET), with <60 cases pathologically reported as of 2017.[1],[2] Thymic mucinous adenocarcinoma is a distinguished carcinoma that is reported in recent years.[3] Primary thymic mucinous adenocarcinoma should be diagnosed by ruling out other primary malignancies. Moreover, chemotherapy for advanced thymic mucinous adenocarcinoma patients is nonconclusive. We present a case of primary thymic mucinous adenocarcinoma with disseminated metastases and rapid progression, resistant to chemotherapy.

  Case Report Top

A 50-year-old male without any underlying disease presented with weight loss of 5% within 3 months and face/neck swelling for 1 month. He visited our emergency department, where computed tomography (CT) revealed huge anterior mediastinal mass (10 cm × 10 cm) with encased superior vena cava (SVC) and adjacent vessels, disseminated enlarged lymph nodes (LNs), and multiple soft-tissue tumors in the peritoneum and pelvic cavity [Figure 1]. CT-guided biopsy for mediastinal tumor revealed adenocarcinoma exhibiting moderate nuclear pleomorphism and focal extracellular mucin production. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin-7 (CK7), but negative for CK20, thyroid transcription factor-1 (TTF-1), paired box gene 8, synaptophysin, and cluster of differentiation-56 (CD56). Reactivity for CD5 and CD117 was focally present [Figure 2] and [Figure 3]. Primary thymic mucinous adenocarcinoma is an extremely rare type of thymic carcinoma. Positron emission tomography-CT was performed in November 2017 to determine the origin of this carcinoma. It revealed no other solid-organ uptake and the following new findings: pericardial and pleural effusions and multiple bone metastases [Figure 4]. Primary thymic mucinous adenocarcinoma with multiple metastases, cT3N3M1 Stage IVB, was diagnosed.
Figure 1: Initial diagnostic computed tomography scan in November 2017

Click here to view
Figure 2: H&E stain

Click here to view
Figure 3: Cluster of differentiation 5 immunohistochemistry stain

Click here to view
Figure 4: Positron emission tomography-computed tomography in November 2017

Click here to view

We performed concurrent chemoradiation (CCRT) with etoposide and cisplatin for severe SVC syndrome. His neck swelling improved gradually, but shortness of breath persisted. Chest X-ray revealed cardiomegaly with progression of pericardial effusion. The January 2018 evaluation after CCRT revealed a mediastinal mass of similar size (9 cm × 9 cm), but multisite LNs, pericardial and bilateral pleural effusion, and abdominal and pelvic metastases were present, along with metastases in the liver, adrenal glands, and pancreas [Figure 5] and [Figure 6]. Pericardial window surgery and pleural effusion drainage were performed with everyday draining 300–500 mL of fluids. Effusion cell block pathology also revealed carcinoma with CK7(+) and CD5(+), compatible with thymic origin. After a family meeting for regimen reimbursed by the National Health System, chemotherapy was switched to paclitaxel and cisplatin. However, therapy still resulted in poor response with persistent pericardial effusions and higher serum carcinoembryonic antigen (CEA) [CEA, 2591.81 ng/mL in January and 3227.05 ng/mL in February 2018; [Figure 7]. The patient felt weaker and received hospice care. He died 1 month after taxane treatment due to infection. The patient's overall survival is 3.5 months from the diagnosis.
Figure 5: Evaluation of computed tomography scan in January 2018

Click here to view
Figure 6: Evaluation of computed tomography scan in January 2018

Click here to view
Figure 7: Carcinoembryonic antigen level

Click here to view

  Discussion Top

Thymic adenocarcinomas have varying malignant potentials that account for 0.48% of all thymic tumors,[1],[2] and mucinous adenocarcinoma (mucinous TET) has been reported as a subtype of nonpapillary adenocarcinomas in the thymus according to the 2004 World Health Organization classification.[3] Mucinous TET has much worse prognosis than papillary adenocarcinoma. Histopathologically, the possible differential diagnoses include rare variant (adenocarcinoma) of thymic carcinoma, direct invasion from pulmonary carcinoma, and metastatic malignancy. The CK7+/CK20− expression profile is used to differentiate the possible primary sites, such as the lung, upper gastrointestinal tract, and pancreaticobiliary tract. The absence of TTF-1 staining contradicts the presence of pulmonary adenocarcinoma. Moreover, reactivity for CD5 or CD117 has been used to confirm thymic origin, while positive results are not entirely specific.[3],[4],[5] In the current case, metastatic adenocarcinoma from the other organs has been excluded based on the clinical and imaging findings. Therefore, the overall histopathological findings are compatible with primary thymic mucinous adenocarcinoma.

Four subtypes of primary mucinous TET have been reported in the Korean literature: mucinous, papillary, papilotubular, and conventional.[6] Mucinous TET was present in 12 of 28 cases. The overall survival of patients who underwent surgical intervention was 11–26 months. Compared with the mucinous subtype, 7 of the 8 patients who presented with papillary carcinoma were alive after treatment, while one died 7 months after the diagnosis. Disseminated metastasis is not discussed in this case review article.[6] Another Japanese case report has simultaneously reviewed 16 prior cases of resectable mucinous TET from 2003 to 2017. They reported that 7 of the 17 patients died after surgery, radiotherapy, or chemotherapy and another four experienced recurrences with no further data on survival.[7] The most reported cases of mucinous TET are in Pan-Asia,[5],[6],[7] probably because of the progress in surgical interventions in Japan. Research activities resulted in better outcomes of thymic malignancy coupled with aggressive surgery.[8]

Mucinous TET is resistant to radiotherapy and chemotherapy, whether it is adjuvant or primary therapy.[1],[6],[7] Chemotherapy regimen for mucinous TET is nonconclusive. In general, CCRT with platinum- and etoposide- or taxane-based regimen is described in case reviews. CCRT with etoposide and cisplatin is effective for small cell lung cancer and thymic carcinoma.[6] Paclitaxel with carboplatin is also recommended with high response rate. For our case, paclitaxel with carboplatin regimen was not reimbursed by the national health system. Our patient refused the taxane regimen until the second-line treatment. His performance worsened with rapid progression of pericardial and pleural effusion. Since the patient was bedridden, he could not tolerate anticancer treatment. Immune checkpoint inhibitors may be the new treatment of choice for patients who are resistant to chemotherapy. Yokoyama and Miyoshi reviewed seven studies of immunotherapy for refractory TET. Pembrolizumab achieves an overall response rate of 24% for TET, but patient selection for immune checkpoint inhibitors needs careful evaluation.[9]

In conclusion, we report a thymic malignancy case of rapid progression with pericardial effusion in the 1st month from the diagnosis, followed by disseminated metastases of solid organs in the 3rd month. This primary mucinous TET was resistant to platinum- and taxane-based chemotherapy. Multiple metastases of mucinous TET were less discussed in prior case reviews. Currently, systemic therapy is generally performed with platinum-based regimen, but new evidence in the administration of immune checkpoint inhibitors to treat this carcinoma is reported in the recent 3 years.[9]

Patients' privacy

The patient (when he was still alive) and his family signed written informed consent for further publication of this case report about rare pathological cancer.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Kwon AY, Han J, Chu J, Choi YS, Jeong BH, Ahn MJ, et al. Histologic characteristics of thymic adenocarcinomas: Clinicopathologic study of a nine-case series and a review of the literature. Pathol Res Pract 2017;213:106-12.  Back to cited text no. 1
Kwon AY, Han J, Cho HY, Kim S, Bang H, Hyeon J. Cytologic characteristics of thymic adenocarcinoma with enteric differentiation: A study of four fine-needle aspiration specimens. J Pathol Transl Med 2017;51:509-12.  Back to cited text no. 2
Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC. World Health Organization Classification of Tumours: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart. Lyon: International Agency for Research on Cancer Press; 2004. p. 183-4.  Back to cited text no. 3
Marx A, Chan JK, Coindre JM, Detterbeck F, Girard N, Harris NL, et al. The 2015 World Health Organization classification of tumors of the thymus: Continuity and changes. J Thorac Oncol 2015;10:1383-95.  Back to cited text no. 4
Moser B, Schiefer AI, Janik S, Marx A, Prosch H, Pohl W, et al. Adenocarcinoma of the thymus, enteric type: Report of 2 cases, and proposal for a novel subtype of thymic carcinoma. Am J Surg Pathol 2015;39:541-8.  Back to cited text no. 5
Cho EN, Park HS, Kim TH, Byun MK, Kim HJ, Ahn CM, et al. A rare case of primary thymic adenocarcinoma mimicking small cell lung cancer. Tuberc Respir Dis (Seoul) 2015;78:112-9.  Back to cited text no. 6
Kinoshita F, Shoji F, Takada K, Toyokawa G, Okamoto T, Yano T, et al. Mucinous adenocarcinoma of the thymus: Report of a case. Gen Thorac Cardiovasc Surg 2018;66:111-5.  Back to cited text no. 7
Okumura M, Shintani Y, Funaki S. Evolution of thymic malignancy management in Japan. Mediastinum 2017;1:9.  Back to cited text no. 8
Yokoyama S, Miyoshi H. Thymic tumors and immune checkpoint inhibitors. J Thorac Dis 2018;10:S1509-15.  Back to cited text no. 9


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
Case Report
Article Figures

 Article Access Statistics
    PDF Downloaded89    
    Comments [Add]    

Recommend this journal